On startup reconcile the hub-served offsite: descriptor into a key-only offbox
target. internal/offsiteapply.Bridge: verify-pin box host key vs host_fingerprint
(NO blind TOFU) → consume the one-time password (single-use, never logged) →
sshpass ssh-copy-id -s -f install + verify → configure offbox → EscrowState=pending
(fork-4 via Manager.ApplyOffsiteTarget) → persist a descriptor-hash marker LAST.
Idempotent + fail-safe. Seams faked in tests; both red-proofs run+reverted.
Dockerfile + sshpass. NOT yet live-applied (supervised end-to-end next runbook).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PSK5g6qYLknKj8u3QAFEr6
